A high-efficient and low-consumption nanoimprint method to prepare large-area and high-quality Nafion array for the ordered MEA of fuel cell

Recently, the third-generation-ordered membrane electrode assembly (MEA) is widely researched, because it can simultaneously provide abundant and continuous ordered charge, proton, and mass transfer channels. However, the development of the ordered MEA is restricted by the preparation of the ordered channels. In this work, we developed a high-efficient (<1 min), contamination-free and low-consumption nanoimprint method to prepare large area (up to 1800 cm 2 ) composite proton exchange membrane (PEM) with ordered Nafion array by repeatedly using porous anodic alumina oxide (AAO) template. Firstly, prepare the ordered Nafion nano-arrays by filling AAO template with low Nafion solution loading (only 0.75 g/m 2 ). Secondly, imprint the ordered Nafion nano-arrays onto the commercial PEM under 140 °C to prepare the composite PEM with Nafion array. Thirdly, demold the composite PEM from the AAO template by using water as clean release agent. Lastly, recycle the AAO template to repeatedly prepare the composite PEM with Nafion array (at least 50 times). This nanoimprint method can prepare abundant composite PEMs by imprinting diverse ordered Nafion array structures on different commercial PEMs. In PEMFC, the composite PEM above has 1.6 times higher performance and one tenth lower hydrogen crossover than the corresponding commercial PEM. This nanoimprint method can be expanded to prepare the arrays on alkaline electrolyte membrane (AEM), PBI membrane and other electrolyte membranes. Furthermore, the application of these membranes can greatly promote the ordered MEA in PEMFC, AEM fuel cell, water electrolysis, and electrochemical synthesis, etc.